I. Field
The present disclosure relates generally to communication, and more specifically to techniques for transmitting a pilot and for performing channel estimation in a communication system.
II. Background
In a wireless communication system, a transmitter typically encodes, interleaves, and modulates (or symbol maps) traffic data to obtain data symbols, which are modulation symbols for data. For a coherent system, the transmitter multiplexes pilot symbols with the data symbols, processes the multiplexed data and pilot symbols to generate a modulated signal, and transmits this signal via a wireless channel. The wireless channel distorts the transmitted signal with a channel response and further degrades the signal with noise and interference.
A receiver receives the transmitted signal and processes the received signal to obtain received data and pilot symbols. For coherent data detection, the receiver estimates the response of the wireless channel based on the received pilot symbols. The receiver then performs data detection (e.g., equalization) on the received data symbols with the channel estimate to obtain data symbol estimates, which are estimates of the data symbols transmitted by the transmitter. The receiver then demodulates, deinterleaves, and decodes the data symbol estimates to obtain decoded data for the transmitter.
The quality of the channel estimate has a large impact on data detection performance and affects the quality of the data symbol estimates as well as the reliability of the decoded data. There is therefore a need in the art for techniques to effectively perform channel estimation in a wireless communication system.